As is well known, cross-corrugated packing is used in certain distillation columns in place of distillation plates, to ensure material and heat exchange between a rising gas and a falling liquid. These cross-corrugated packings are constituted by a superposition of sections. Each section is formed by a stack of corrugated strips each disposed in a ith generally vertical plane, one against the others. The corrugations are oblique and descend in opposite directions from one strip to the next.
The strips generally comprise dense small diameter perforations, with a perforation proportion of about 10l, to permit the liquid to flow on opposite sides of the corrugated strips.
British 1,004,046 and Canadian 1,095,827 disclose such cross-corrugated packings.
A cross-corrugated packing is generally produced from a flat product, namely metallic sheets in the form of strips. The strips are first bent (or folded) so as to form a corrugated metal sheet in a strip whose corrugations are oblique relative to the axis of the strip. The bent strips are then cut off in sections, then stacked alternately reversed. The packing sections thus obtained are often called "packs".
WO-A-90/10 497 discloses among other things a packing analogous to the mentioned cross-corrugated packings, but perforated in a different way. The term "cross-corrugated packing" used here also comprises such a packing, as well as any analogous packing.
Oil platforms at sea produce residual gases. For economic and environmental reasons, it is becoming more and more necessary to recover these gases, one method consists in their conversion into heavier hydrocarbons, in liquid form and hence more easily transportable, by the Fischer-Tropsch process, which consumes large quantities of oxygen.